cannot retrieve data from 2 tables getting no result - php

Question

I have 2 tables:
competition_winners where I am storing people who won competition and table competition where I am storing info about actual competition.
So I am retrieving winners and competition's end date. But the query responsible for date doesn't return anything. I am using Opencart so performing query in model. Here is its code.
public function getWinnersByDate($date) {
$qr = "SELECT competition_id FROM " . DB_PREFIX . "competition_winners";
//$fcid = $qr->row['competition_id'];
$query = "SELECT cometition_id,end_date FROM " . DB_PREFIX . "competition WHERE competition_id = '" .$qr->row['competition_id'] . "'";
return $query->row;
Query works fine in PhpMyadmin. What am I missing or doing wrong?

Answer 1

Instead of running this in two queries You should be using JOIN (search about SQL JOIN on google).
public function getWinnersByDate($date) {
$qr = $this->db->query("
SELECT cw.competition_id, c.end_date
FROM " . DB_PREFIX . "competition_winners cw
LEFT JOIN " . DB_PREFIX . "competition c ON c.competition_id = cw.competition_id
");
return $query->rows;
}
I do not know Your DB structure, but the query above has no sense in it's current state - I believe You want to add some WHERE clause using the provided $date argument and that You want to select more information from competition_winners table, so please, either do it Yourself or provide us with more details on Your problem.